drivers/mmc/core/host.c

   1 /*
   2  *  linux/drivers/mmc/core/host.c
   3  *
   4  *  Copyright (C) 2003 Russell King, All Rights Reserved.
   5  *  Copyright (C) 2007-2008 Pierre Ossman
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  *  MMC host class device management
  12  */
  13
  14 #include <linux/device.h>
  15 #include <linux/err.h>
  16 #include <linux/idr.h>
  17 #include <linux/pagemap.h>
  18 #include <linux/leds.h>
  19 #include <linux/slab.h>
  20
  21 #include <linux/mmc/host.h>
  22
  23 #include "core.h"
  24 #include "host.h"
  25
  26 #define cls_dev_to_mmc_host(d)  container_of(d, struct mmc_host, class_dev)
  27
  28 static void mmc_host_classdev_release(struct device *dev)
  29 {
  30         struct mmc_host *host = cls_dev_to_mmc_host(dev);
  31         kfree(host);
  32 }
  33
  34 static struct class mmc_host_class = {
  35         .name           = "mmc_host",
  36         .dev_release    = mmc_host_classdev_release,
  37 };
  38
  39 int mmc_register_host_class(void)
  40 {
  41         return class_register(&mmc_host_class);
  42 }
  43
  44 void mmc_unregister_host_class(void)
  45 {
  46         class_unregister(&mmc_host_class);
  47 }
  48
  49 static DEFINE_IDR(mmc_host_idr);
  50 static DEFINE_SPINLOCK(mmc_host_lock);
  51
  52 /**
  53  *      mmc_alloc_host - initialise the per-host structure.
  54  *      @extra: sizeof private data structure
  55  *      @dev: pointer to host device model structure
  56  *
  57  *      Initialise the per-host structure.
  58  */
  59 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
  60 {
  61         int err;
  62         struct mmc_host *host;
  63
  64         if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
  65                 return NULL;
  66
  67         host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
  68         if (!host)
  69                 return NULL;
  70
  71         spin_lock(&mmc_host_lock);
  72         err = idr_get_new(&mmc_host_idr, host, &host->index);
  73         spin_unlock(&mmc_host_lock);
  74         if (err)
  75                 goto free;
  76
  77         dev_set_name(&host->class_dev, "mmc%d", host->index);
  78
  79         host->parent = dev;
  80         host->class_dev.parent = dev;
  81         host->class_dev.class = &mmc_host_class;
  82         device_initialize(&host->class_dev);
  83
  84         spin_lock_init(&host->lock);
  85         init_waitqueue_head(&host->wq);
  86         INIT_DELAYED_WORK(&host->detect, mmc_rescan);
  87         INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable);
  88
  89         /*
  90          * By default, hosts do not support SGIO or large requests.
  91          * They have to set these according to their abilities.
  92          */
  93         host->max_hw_segs = 1;
  94         host->max_phys_segs = 1;
  95         host->max_seg_size = PAGE_CACHE_SIZE;
  96
  97         host->max_req_size = PAGE_CACHE_SIZE;
  98         host->max_blk_size = 512;
  99         host->max_blk_count = PAGE_CACHE_SIZE / 512;
 100
 101         return host;
 102
 103 free:
 104         kfree(host);
 105         return NULL;
 106 }
 107
 108 EXPORT_SYMBOL(mmc_alloc_host);
 109
 110 /**
 111  *      mmc_add_host - initialise host hardware
 112  *      @host: mmc host
 113  *
 114  *      Register the host with the driver model. The host must be
 115  *      prepared to start servicing requests before this function
 116  *      completes.
 117  */
 118 int mmc_add_host(struct mmc_host *host)
 119 {
 120         int err;
 121
 122         WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
 123                 !host->ops->enable_sdio_irq);
 124
 125         led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
 126
 127         err = device_add(&host->class_dev);
 128         if (err)
 129                 return err;
 130
 131 #ifdef CONFIG_DEBUG_FS
 132         mmc_add_host_debugfs(host);
 133 #endif
 134
 135         mmc_start_host(host);
 136
 137         return 0;
 138 }
 139
 140 EXPORT_SYMBOL(mmc_add_host);
 141
 142 /**
 143  *      mmc_remove_host - remove host hardware
 144  *      @host: mmc host
 145  *
 146  *      Unregister and remove all cards associated with this host,
 147  *      and power down the MMC bus. No new requests will be issued
 148  *      after this function has returned.
 149  */
 150 void mmc_remove_host(struct mmc_host *host)
 151 {
 152         mmc_stop_host(host);
 153
 154 #ifdef CONFIG_DEBUG_FS
 155         mmc_remove_host_debugfs(host);
 156 #endif
 157
 158         device_del(&host->class_dev);
 159
 160         led_trigger_unregister_simple(host->led);
 161 }
 162
 163 EXPORT_SYMBOL(mmc_remove_host);
 164
 165 /**
 166  *      mmc_free_host - free the host structure
 167  *      @host: mmc host
 168  *
 169  *      Free the host once all references to it have been dropped.
 170  */
 171 void mmc_free_host(struct mmc_host *host)
 172 {
 173         spin_lock(&mmc_host_lock);
 174         idr_remove(&mmc_host_idr, host->index);
 175         spin_unlock(&mmc_host_lock);
 176
 177         put_device(&host->class_dev);
 178 }
 179
 180 EXPORT_SYMBOL(mmc_free_host);
 181